Appeal for Advice

So, I have a problem. I've talked to a couple of sources about it, but have come up short. I have yet to google it, because, honestly, I'm not sure what search would even work. Therefore, I have decided to lay it out and hope someone on the grand world wide web might have and idea...

I gave blood a month ago and that elbow has been sore and stiff ever since! I've talked to the red cross and they just said to apply moist heat. I've applied moist heat. I've been wary of working out---ok, I just haven't worked out... but I finally did this past week and its still sore and stiff! And to top it all off, the people looked really nervous as I was giving blood and I think the girl who stuck me was new because the other people were watching her very carefully... details which have not eased my anxiety about my elbow.

Any ideas?!?!?